The present invention generally relates to contraception and/or sterilization, and more particularly to temporary or permanent intrafallopian contraceptive devices, delivery systems, and non-surgical methods for their deployment.
While the theoretical effectiveness of existing non-surgical contraceptive techniques, including barrier methods and hormonal therapies, is well established, the actual effectiveness of most known methods is disappointing. One reason for these disappointing results is that many of the presently available methods for inhibiting pregnancy without surgery depend upon significant user involvement. Non-compliance typically results in quite high rates of failure, and overcoming user non-compliance to improve overall efficacy has proven quite difficult.
One form of long term contraception which is less susceptible to user non-compliance is the intrauterine device (IUD). IUDs have been found to have higher rates of reliability, and are effective for a longer period of time, then most other commercially available contraceptives. Unfortunately, IUDs are also associated with serious infectious complications. For this reason, the use of IUDs within the United States has decreased dramatically. Additionally, IUDs are subject to unplanned expulsion, and are removed due to excessive pain or bleeding in a significant percentage of cases, further reducing acceptance of the IUD as a method of inhibiting pregnancy.
Commercially available options for permanent sterilization include fallopian tube ligation and vasectomy. These methods are surgical and are not available to many people in the world. It is common knowledge that fertilization occurs in the fallopian tubes where the sperm and ovum meet. Tubal ligation avoids this by surgical and complete occlusion of the fallopian tubes.
In work done in connection with the present invention, it has previously been proposed to transcervically introduce a resilient coil into a fallopian tube so as to inhibit conception. PCT Patent Application No. 99/15116, assigned to the present assignee (the full disclosure of which is incorporated herein by reference) describes devices which are transcervically inserted into a tubal ostium and mechanically anchored within the fallopian tube. The described devices may promote a tissue ingrowth network to provide long term conception and/or permanent sterilization without the need for surgical procedures, and should avoid the risks of increased bleeding, pain, and infection associated with intrauterine devices.
While the recently proposed intrafallopian contraceptive devices represent a significant advancement in the art, still further improvements would be desirable. In general, it would be desirable to provide improved non-surgical devices, systems, and methods for inhibiting pregnancy. It would be beneficial if these improved techniques increased the ease with which these contraceptive devices could be deployed, and if the improvements further enhanced the long term retention of the contraceptive device once it has been deployed. It would be further beneficial if these improved access and deployment techniques were suitable for a wide variety of physiological geometries, ideally without having to tailor the device, deployment system, or deployment method for specific individuals. Some or all of these advantages are provided by the devices and methods described hereinbelow.